Remotely controllable current regulator apparatus



Oct. 11, 1966 o. M. HART 3,278,835

REMOTELY CONTROLLABLE CURRENT REGULATOR APPARATUS Original Filed Sept.21. 1962 8 Sheets-Sheet l INVENTOR BYJMMJW ATTORNEYS S m m 5 2 N m R H am mm Vm mm NU m m H N! ONm m @V m W Ah m om & m H A m w M J 3 M w m a P-1 w 8 v u no L m .|I.l. 0 J m G E T R R T A N Y H m B w Q A L L O R T wC 02 m E T W :1- m

WU m Om Oct. 11, 1966 Original Filed Sept. 21. 1962 Oct. 11, 1966 o. M.HART 3,278,835

REMOTELY CONTROLLABLE CURRENT REGULATOR APPARATUS Original Filed Sept.21, 1962 8 Sheets-Sheet 4 INVENTOR 0 via M. HA

BY 5 /Jm ATTORNEYS 0. M. HART Oct. 11, 1966 REMOTELY CONTROLLABLECURRENT REGULATOR APPARATUS 8 Sheets-Sheet 5 Original Filed Sept. 21,1962 INVENTOR PN v Ouvsa H HEF ATTORNEYS Oct. 11, 1966 o. M. HART3,278,835

REMOTELY CONTROLLABLE CURRENT REGULATOR APPARATUS Original Filed Sept.21. 1962 8 Sheets-Sheet 6 FIGJJ.

INVENTOR @uvaa M. [v /n17 BY m ATTORNEYS Oct 1955 o. M. HART 3,278,835

REMOTELY CONTROLLABLE CURRENT REGULATOR APPARATUS Original Filed Sept.21, 1962 E5 IIGJS flgo FUSE 8 Sheets-Sheet 8 QEMOTELY CON ROLLHBLESWITCH 23s aao "l3 EIN am 7 T J 380 130 o/ W401 351 REMOTELYCONTROLLHBLE MANUAL M0102 OPERATED MOTOQ g sumcu 3G5 SUMTCH q6 34 35f P405 8 -gqg 404 403 437 INVENTOR ATTORNEYJ United States Patent 3,278,835REMOTELY CONTROLLABLE CURRENT REGULATOR APPARATUS Oliver M. Hart,Cornwall Bridge, Conn. Continuation of application Ser. No. 225,269,Sept. 21, 1962. This application Nov. 29, 1965, Ser. No. 516,204

6 Claims. (Cl. 32394) This application is a continuation application ofmy copending U.S. patent application, Serial No. 225,269, filedSeptember 21, 1962, now abandoned.

The present invention relates to new and novel remotely controllablecurrent regulator apparatus and more particularly to apparatus which isespecially adapted to supply current to welding equipment.

The present invention is particularly adapted for use in multi-operatorwelding systems wherein a constant electrical potential is provided, andsome sort of current regulator is utilized by the individual welders forcontrolling the amount of welding current in accordance with theparticular job situation.

It has been a common practice in the prior art to provide currentregulators which can be manually adjusted so as to regulate the weldingcurrent by certain increments so as to obtain optimum Weldingconditions. Such regulators generally have taken the form of variableresistors which are controlled by manually operated.

switches so as to adjust the amount of welding current. Many of thesedevices are limited in use because of the fact that the switch means isadapted only for adjusting the current Within certain limits, and inmany cases, the optimum welding current can not be accurately obtainedbecause the switch means does not permit a sufiiciently fine adjustment.

It is accordingly a feature of the present invention to provide anarrangement whereby the welding current can be adjusted in very smallincrements whereby the optimum-welding conditions can be readilyobtained.

;A first important consideration has arisen particularly in recent yearswhen welding is carried out with certain new and exotic metals. Inpresent day technology, many of the materials employed are difiicult toweld and raise special welding problems wherein the welding currentbecomes a critical feature. In fact, the welding current becomes socritical in many instances that in order to obtain the desired weld, itis necessary for the individual welder to continuously adjust theWelding current in accordance with the thickness of the material beingwelded and various other operating conditions.

Accordingly, the present invention is especially constructed to providean arrangement which permits the welding current to be continuouslychanged while the welding operation is being carried out. In order toaccomplish this desired result, a remotely controllable switch means isprovided which may be readily operated by the foot of a welder such thatthe welder can remotely control the current regulator apparatus so as tochange the welding current in small increments while he is weldingthereby ensuring that optimum welding conditions will be provided at alltimes.

The present invention incorporates an arrangement wherein the apparatuscomprises a compact unit having an input means which is adapted to beconnected to a suitable source of electrical energy such as a constant80 volt DC power source. The apparatus also includes an output which isadapted to be connected by means of a conventional welding cable to mysuitable welding equipment. On the other hand, it should also be clearlyunderstood that the apparatus is not limited to use with weldingsystems, but can be used in any application wherein it is desired toremotely regulate the current.

3,278,835 Patented Oct. 11, 1966 A first plurality of resistances areprovided between the input and the output means, these resistancesprovid ing rather large steps in the amount of amperage pro videdtherethrough, each of these resistances being connectable with theoutput means by individually manu-. ally controllable switches. Inaddition, a second resistance means is provided which has many leadstapped thereinto at various points therealong such that each of theleads is adapted to carry a different amount of current in relativelysmall increments. For example, the large resistances previouslymentioned may provide 40 ampere increments of adjustment, whereas theleads later referred to may carry current in increments of 2 amperesdifference.

These various latter leads are in turn connected with a remotelyoperable switch means which is adapted to sequentially connect the leadsto the output so as to vary the output current over a relatively widerange of occurrence in small steps.

The remotely operated switch means is driven by a power operated devicesuch as an electric motor, operation of the electric motor beingcontrolled from a remote foot switch as previously described.

Limit stop means is also provided for limiting the movement of theremotely controlled switch in opposite directions while a manuallyoperable switch is mounted directly on the unit to provide an auxiliarycontrol for the drive motor.

In the present invention, the second resistance means referred to aboveactually comprises a dual system wherein two parallel sets ofresistances are provided as will hereinafter more clearly appear, eachof these parallel resistance paths being adapted to carry half of thecurrent. It should be noted that this dual system could actually bereplaced by a single system which would carry all of the current, thedual arrangement being provided because of certain design considerationswhich permit the over-all dimensions of the apparatus to be drasticallyreduced thereby making a much more compact and cheaper arrangement froma construction standpoint.

An object of the present invention is to provide a new and novelremotely controllable current regulator which is particularly adaptedfor use with welding equipment and which includes switch means forproviding a readily adjustable current over a wide range.

Another object of the invention is the provision of a remotelycontrollable current regulator including means for remotely controllingthe adjustment of the current in relatively small increments ofamperage.

A further object of the invention is to provide limit stop means forlimiting the movement of the remotely controlled switch means of theinvention in opposite directions.

A still further object of the invention is to provide remotelycontrollable current regulator apparatus which is relatively simple andinexpensive in construction and yet quite sturdy and reliable in use.

Other objects and many attendant advantages of the invention will becomemore apparent when considered in connection with the specification andaccompanying drawings, wherein:

FIG. 1 is a top perspective view of the over-all unit of the presentinvention;

FIG. 2 is a front view of the unit shown in FIG. 1;

FIG. 3 is a top view of the unit with the cover member removed;

FIG. 4 is a bottom view of the unit;

FIG. 5 is a section view taken substantially along line 55 of FIG. 7looking in the direction of the arrows;

FIG. 6 is a view taken substantially along line 66 of FIG. 7 looking inthe direction of the arrows;

FIG. 7 is a side view of the apparatus with the side wall portionthereof removed for the sake of clarity;

FIG. 8 is a sectional view taken substantially along line 88 of FIG. 7looking in the direction of the arrows;

FIG. 9 is a sectional view taken substantially along line 9-9 of FIG. 7looking in the direction of the arrows;

FIG. 10 is a sectional view taken substantially along line 1010 of FIG.7 looking in the direction of the arrows;

FIG. 11 is a sectional view taken substantially along line 1111 of FIG.10 looking in the direction of the arrows;

FIG. 12 is a sectional view taken substantially along line 12-12 of FIG.10 looking in the direction of the arrows;

FIG. 13 is a sectional view taken substantially along line 1313 of FIG.12 looking in the direction of the arrows;

FIG. 14 is a sectional view taken substantially along line 1414 of FIG.12 looking in the direction of the arrows;

FIG. 15 is a schematic wiring diagram indicating diagrammatically thegeneral resistance wiring arrangement of the present invention; and

FIG. 16 is a schematic wiring diagram indicating schematically thewiring for operating of the remotely controlled switch means.

Referring now to the drawings wherein like reference charactersdesignate corresponding parts throughout the several views, as seen mostclearly in FIGS. 1-7 inclusive, a supporting framework for the unitaccording to the present invention comprises a supporting base indicatedgenerally by reference numeral 20, this base portion being substantiallyrectangular in configuration and comprising a pair of longitudinallyextending channel portions 21 and 22 which are connected at the oppositeends there- .of by a pair of transverse channel portions 23 and 24,these various channel portions being suitably secured to one another asby Welding or the like to form a rigid rectangular frame.

A sheet of expanded metal 25 is supported on the inwardly extending legportions of the various channels and suitably secured thereon so as toprevent the entry of undesired objects into the under portion of theapparatus. Four similar leg portions 27 are disposed at the four cornersof the support base a suitable distance above the supporting surface soas to permit free circulation of air through the expanded metal of thesupporting base to cool the apparatus. It should be understood that thesupporting base may be eliminated in certain instances wherein'theremaining apparatus could be supported for example in a drawer or amulti-unit resistor assembly or the like. A supporting framework isdisposed on the base, this supporting framework comprising a front plate30, an intermediate plate 31 and a back plate 32 .as seen in FIG. 7, thelower lateral portions of these plates being joined by lower sidechannel members 35 and 36 as seen in'FIGS. 5 and 6 which extendlongitudinally from the front plate to the back plate, these lower sidechannel members being suitably secured to each of plates 30, 31 and 32as by welding and the like.

A pair of upper side frame members comprising barlike members 39 and 40which extend from the front plate to the rear plate and which aresecured to'the plates 31 and 32 as by welding and the like. A firstvertically extending member 42 is secured between members and 39 of theframe and has a lifting handle 43 pivotally supported thereon.

A second vertically extending member 44 similar to member 42 is securedbetween members 36 and and has a lifting handle 45 pivotally securedthereto. Obviously, handles 43 and 45 may be utilized for lifting theentire framework out of the base, if desired, and on the other hand thebase may be secured to the framework as by suitable bolts or the like ifdesired.

A vertically extending motor support member 48 as I seen in FIG. 10 issecured between members 35 and 39 adjacent the front plate 30 of theapparatus and serves to support a motor hereinafter described. A firstcover plate 49 is removably secured to the outer surface of members 35and 39 as by bolts or the like and closes the lateral space betweenfront plate 30 and intermediate plate 31. A similar cover plate 50 isremovably secured to the outer surfaces of members 36 and 40 of theframework as by bolts or the like and similarly closes the space betweenfront plate 30 and intermediate plate 31 on the opposite side of theframework.

As seen in FIGS. 5 and 6, a first sheet of expanded metal 53 is securedto the inner surfaces of members 35 and 39 and extends verticallybetween these members from a point adjacent intermediate plate 31 to apoint adjacent rear plate 32. A similar sheet of expanded metal 54 issecured to the inner surfaces of members 40 and 36 and extendstherebetween from a point adjacent intermediate wall 31 to a pointadjacent rear wall 32.

These sheets of expanded metal will prevent the entry of undesiredobjects into the apparatus. A cover indicated generally by referencenumeral 55 as seen in FIGS. 1 and 2 is provided for the over-allapparatus, cover 55 being peaked so as to provide an apex portion 56,the cover also including depending flange portions 57 and 58 whichextend downwardly along the side portions of the framework. Cover member55 is of such a dimension that it includes a longitudinally extendingportion 60 which extends forwardly of the front plate 30 of theapparatus a substantial distance so as to protect those portions of theapparatus which extend forwardly of the front plate, the overhangingportion 60 preventing external objects from dropping downwardly uponthese components. Cover 55 is also provided with a plurality ofstruck-out vents 62 which permit air to circulate through the covermember and downwardly into the apparatus.

It is apparent that the structure thus far described provides'a veryrigid protective framework which prevents any damage to the apparatusand at the same time adequate provision is provided for air circulationto ensure that the apparatus does not become overheated during use.

An input means as seen in FIG. 3 indicated generally by referencenumeral 65 includes a portion 66 of insulating material which is securedas by means of nut and bolt assembly 67 to the rear plate 32 of theframework,

this insulated portion extending through a suitable opening provided inthe rear plate and including an outward- 1y extending electricalconnector portion 70 which is adapted to be connected to a suitableelectrical connector portion of conventional construction. It will beapparent that the input means can be of any desired construction as longas it is adapted to be connected to a suitable source of power. Theelectrical connector portion extends inwardly and is attached by meansof nuts 71 and 72 to a bus bar means or connector plate 73, plate 73being supported in position by the nuts 71 and 72.

A first resistance means as seen in FIG. 3 has the rear end portionthereof connected to bus bar means 73 as by silver soldering and thelike, the opposite end of this resistance means being connected to aconnector member 81 more fully hereinafter described.

Resistance means 80 may comprise a resistance coil of No. 7 Nichromewire in the form of a continuous coil having 52 turns. This coil issupported upona plurality of insulator blocks 83 which are shown asbeing 4 in number, these insulator blocks being formed of a suitableinsulating material such as porcelain or the like and having arelatively flattened cross-sectional configuration with substantiallycylindrical peripheral surface portions which define only a smallportion of the surface of a complete cylinder. These surface portionshave grooves 85 formed therein which are substantially in the locus of aportion of the rod adjacent rear plate 32 being threaded to receive anouter nut member 89 and an inner nut member 90 for retaining the rod inposition. Sleeves 92 of suitable insulating material such as plastic andthe like are disposed about the opposite ends of the rod adjacent theintermediate and the rear plates for limiting the movement of theresistance coil 80 toward these plates. Insulator blocks 83 are spacedfrom one another so as to be freely slidable on rod 87 whereby expansionand contraction of resistance coil 80 may occur during op eration of theapparatus.

Three similar resistance coils 100, 101 and 102 are provided, theseresistance coils each being connected at the rear end portions thereofto bus bar means 73 and being connected at the forward end thereof toconnector members 103, 104 and 105 respectively which will behereinafter more fully described.

Each of resistance coils 100, 101 and 102 may comprise a No. 4 Nichromewire defining a continuous coil of 50 turns. Coils 100, 101 and 102 arerespectively mounted upon insulator blocks 110, 111 and 112 which may beof the same construction as the insulator blocks 83 previouslydescribed. Insulator blocks 110, 111 and 112 are in turn mounted uponrods 113, 114 and 115 respectively which are supported betweenintermediate plate 31 and rear plate 32, the rods being received withinsuitable openings provided in these plates. Each of rods 113, 114 and115 is provided with threads thereon adjacent the rear plate, and rod113 is held in place by means of outer and inner nut means 113 and 113"while rod 114 is held in place by means of outer and inner nut means 114and 114" and rod 11.5 is held in place by means of outer and inner nutmeans 115 and 115".

Insulating sleeves 117 of suitable material such as plastic or the likeare disposed about opposite end portions of rod 113, similar insulatingsleeves 118 and 119 being provided about opposite ends of rods 114 and115 respectively.

A supporting panel member 112 as seen in FIG. 3 formed of suitableinsulating material such as plastic or the like is supported on thefront plate 30 by a pair of nut and bolt assemblies 124, 125.

An elongated bus bar 126 is provided, this bus bar 126 having alaterally extending extension 127 at one end portion thereof. Bus bar126 is supported upon member 122 by means of nut and bolt assemblies130, these nuts extending through suitable openings provided in members122 and 126. 1

Member 122 is maintained in spaced relationship with respect to frontplate 30 by means of a pair of spacer members 124' and 125' havingopenings therethrough through which the nuts of nut and bolt assemblies124 and 125 extend.

Four spaced spring clip contact members 131, 132, 133 and 134 aresecured to bus bar 126 by means of nut and bolt assemblies 135, thespring contact members being of conventional construction andincluding'a pair of spaced legs between which a blade-type switch isadapted to be inserted, the natural resiliency of the contacts servingto tightly grip the blade-type switch between such leg portions.

The base portions of these spring clip contacts as most clearly seen inFIG. 3 are widened so as to readily receive the nut and bolt assembliesfor securing them in operative position. As seen in FIG. 11, member 122is provided with openings 136 which are adapted to receive the enlargedheads of the bolts of the nut and bolt assemblies 135.

As seen in FIG. 3, each of connector members 81, 103, 104 and 105 are ofgenerally L-shaped configuration with one leg of the L operativelyconnected with the forward end of one of the resistance means 80, 100,101 and 102 while the other leg of the connector extends for- Wardlythrough suitable openings provided through a heat insulating baffleplate 140 formed of asbestos or the like and secured to the rear face ofintermediate wall 31, the openings in intermediate plate 31 beingconsiderably larger than the forwardly extending portions of theconnectors and the connectors being supported adjacent these forwardends of each of connectors 81, 103, 104 and are turned upwardly in asimilar manner, the construction of connector 104 being seen mostclearly in FIG. 11 wherein the upturned end portion is indicated byreference numeral 104'. Four spring clip contact members 145, 146, 147and 148 as seen in FIG. 10 are supported at the lower portion of member122 as seen in FIG. 11 directly beneath the previously described springclip contact members by means of nut and bolt assemblies 150 whichextend through suitable threaded openings provided in the base portionsof the spring clip contact members and aligned threaded openingsprovided in the upstanding portions of the associated connector membersadjacent thereto. In this manner, the lower spring contact mem bers areelectrically connected with the forward ends of connectors 81, 103, 104and 105, and are rigidly held in position relative to support panelmember 122.

Four blade switch members 152, 153, 154 and 155 as seen in FIG. 10 arepivotally supported by the leg portions of spring clip contact members145, 146, 147 and 148 respectively by means of headed studs 157 whichare threaded at the outer ends thereof and receive thereon nut members158, studs 157 extending through suitable openings provided in the legportions of the various spring clip members.

As 'seenparticularly in FIG. 11, plate switch member 154 is connected tothe outer bifurcated end portion of member 160 by means of a headed stud161 which may be held in place by means of a hairpin-like spring 163 asseen in FIG. 10 seated within a suitable circumferential groove providedin the stud, this stud extending through suitable openings provided insuch bifurcated end portion of the switch member.

Member 160 is embedded in the inner end portion of a switch handleindicated generally by reference numeral 166 formed of Bakelite or asimilar insulating material, the switch handle defining an annularshoulder 167 for limiting inward movement of the switch handle, theswitch handle also having an enlarged manually graspable knob portion169 at the outer end thereof.

Three other similar switch handles are indicated generally by referencenumerals 170, 171 and 172 as seen in FIGS. 2 and 3, these switch handlesin turn being operatively connected with blade switch members 152, 153and 155 respectively in the identical manner in which switch handle 166is connected with blade switch member 154. In each case the inwardlyextending portion of the switch handle extends through an opening inpanel support member 122 and is freely slidable with respect to member122 onthe front plate 30 of the framework so that the blade switchmembers can readily be moved from the full line position as shown inFIG. 11 wherein the switches are disconnected from the bus bar 129 tothe phantom line position shown in this figure where the switches areoperatively connected with the bus bar 126.

An output means is indicated generally by reference numeral 175 as seenin FIG. 3 and includes a body of insulating material which is supportedon the front plate 30 by means of nut and bolt assemblies 177. Thisoutput means includes an electrical connector member 180 formed ofsuitable electrically conductive material which extends inwardly of theinsulating body, this inwardly extending portion 181 being connected bymeans of nut and bolt assemblies 182 to a connector member 185 formed ofconductive material which is supported at the lower portion thereof byan insulator member 187 secured to the front plate 30. Connector member185 includes an upwardly extending projection 188 as seen in FIG. whichis connected with the lower end of a fuse 190, the upper end of which isconnected to the lateral extension 127 of bus bar 126.

Referring now to FIG. 15, it will be seen that operation of the bladeswitches 152, 153, 154, and 155 is adapted to connect different ones ofresistances 80, 100, 101 and 102 between the input 65 and output 175.The resistances are so designed as described previously that closing ofswitch 152 will provide 40 amperes of current to the output when thedevice is connected with a constant 80 volt D.C. power source. Each ofswitches 153, 154 and 155 will individually provide a current of 80amperes to the output when closed. It is accordingly evident thatclosing of different combinations of these switches is adapted toprovide output currents varying in 40 ampere increments from 40 amperesto 280 amperes.

A second resistance network is provided for providing small incrementsof amperage and as mentioned previously this network includes adual'path. Referring now particularly to FIG. 4 a first path in thislatter network includes a first resistance coil 200 which has the rearend portion thereof operatively connected with bus bar means 73. Coil200 may be formed of No. 10 Nichrome wire with 47 /2 turns. This coil ismounted upon insulator blocks 201 similar to those previously described,these insulator blocks being mounted upon a rod 202 similar to the rodspreviously described and supported between the intermediate and rearplates 31 and 32, the rod being held in place by nuts 203 threaded onthe outer threaded end of the rod, insulating sleeves 204 and 205 beingdisposed about opposite ends of the rod. A coil 208 formed of Nichromewire is supported upon suitable insulator blocks 210 mounted on a rod211, this rod being held in place by nuts 212 and having insulatingsleeves 213 disposed about opposite ends thereof. A further resistorcoil 215 formed of Nichrome wire is mounted upon insulator blocks 216which are in turn disposed on a rod 217 held in place by nuts 218, therod having insulating sleeves 220 disposed about opposite ends thereof.

a The forward end of coil 200 is connected with the forward end of coil208 in turn being connected with the rear end of coil 215. It isaccordingly apparent that coils 200, 208 and 215 are connected in serieswith one another. Coil 208 is a composite coil formed of a plurality ofdifferent sized wires all connected in series. The coil consists of thefollowing sequence of wires connected in series from the forward endthereof to the rearward end thereof as seen in the drawings. Firstly,turns of No. 10 Nichrome wire are provided which is in turn connectedwith 10 turns of No. 12 Nichrome wire in turn connected with 15 turns ofNo. 13 wire in turn connected with 24 turns of N0. 16 wire which is inturn connected with 10 turns of No. 20 wire.

Referring now particularly to FIG. 9, a section through coil 208illustrates the flattened cross sectional configuration of insulatorblocks 210, and seen at the bottom of this figure is a typical coppertap indicated by reference numeral 222. These copper taps are tappedinto the coil at suitable locations therealong so as to provide thedesired incremental steps of amperage which as discussed previously maybe 2 amperes in the present case. There are 21 such copper tapsconnected with coil 208 at the locations indicated by the dots on FIG.4. All of these taps have not been shown in detail for the sake ofclarity, it being understood that the taps may be spaced about theperiphery of the coil as required in order to provide room for the leadsattached thereto. In addition, the leads from these taps have beeneliminated from the drawings in order to clarify the illustration, itbeing understood that a lead will extend from each of the taps to theremotely controlled switch means hereinafter described.

Coil 215 is also a composite coil and comprises a plurality of wires ofdifferent size connected in series and commencing at the rear endportion of the coil and moving forwardly thereof. The coil consistsfirst of 12 turns of No. 20 Nichrome wire in turn connected with 53turns of No. 24 Nichrome wire. The coil is provided with four coppertaps as indicated by the dots on the drawing. Each of the tapsassociated with coils 208 and 215 are connected with suitable leadswhich may be bound into a bundle indicated generally by referencenumeral 225 as seen in FIG. 5, this bundle of leads passing throughsuitable openings in the intermediate plate 31 and the insulating sheet140, the individual leads 225' thereof being illustrated in FIG. 3 andbeing connected with the upper portion of the remotely controlled switchmeans as hereinafter described.

The other half of the dual path of this second resistance means isidentical with that just described, and accordingly a detaileddescription thereof is not necessary. The components there-of areidentical with those previously described and have been given the samereference numerals primed. It is accordingly apparent that the coils201, 208' and 215' correspond exactly to and are identical with coils200, 208 and 215 respectively and are interconnected in the same mannerand provided with taps in the same manner. Each of the taps associatedwith coils 208' and 215' is provided with an individual lead, thesevarious leads being collected in a bundle 227 which also extends throughsuitable openings provided in members 31 and 140, the individual leads227 of this bundle then in turn being connected with the lower portionof the remotely controlled switch means as indicated in FIG. 4.

The remotely controlled switch means as seen most clearly in FIGS. 1214inclusive indicated generally by reference numeral 230 includes aforward wall portion 232, rear wall portion 233, an upper wall portion234 and a lower wall portion 235, the ends of the switch means beingclosed by end walls 236 and 237. All of these wall portions are formedof a suitable insulating material such as plastic and the like.

Front wall portion 232 is secured to the front plate 30 by means of nutand bolt assemblies 240 as seen in FIG. 2, the walls 236 and 237 beingsecured to the front wall 232 by means of screws 236' and 237' as seenin FIG. 12 which are threaded into suitable threaded openings providedin the respective end walls. Rear wall 233 and a retaining plate 240 ofa rigid material such as metal are secured to the end walls 236 and 237by means of screws 242 and 243 threaded into suitable tapped openings inthe end walls 236 and 237 respectively.

Top wall portion 234 is secured to the opposite end walls 236 and 237 byscrews 245 and 246 respectively as seen in FIG. 10 which are threadedinto suitable tapped openings provided in the respective end walls. Thelower wall 235 is likewise secured in position by means of screws 247and 248 which extend into tapped openings formed in the under surface ofthe walls 236 and 237 respectively.

A common contact member 250 as seen in FIG. 12

extends substantially throughout the length of the switch means and issecured to the inner surface of front wall 232 by a plurality of screws251 which are threaded into suitable tapped openings provided in the busbar 250. It should be noted that insulating spacers 253 as seen in FIG.4 are provided for spacing the forward surface of front wall 232 of theremotely controlled switch means from the front plate 30 so as to ensurethat the remotely controlled switch means will be completely insulatedfrom the front plate.

Bus bar 250 as seen in FIG. 13 extends upwardly through a notch cut intop wall 234 and includes a laterally extending projecting portion 255.This portion 255 is connected by means of a jumper 256 with bus bar 126previously described.

A plurality of electrically conductive laminates 260 as seen in FIG. 12formed of copper or a similar good conductor are provided, theseelectrically conductive laminates being electrically insulated from oneanother by means of laminates 261 formed of suitable insulating materialsuch as Bakelite or the like. As shown, suflicient laminates 261) areprovided for connection to each of the leads 225 or 227' previouslydescribed, and in the present example as given, 25 such leads areprovided and accordingly 25 laminates 261 areavailable. A pair oflongitudinally extending securing rods 265 and 266 as seen in FIG. 13are provided, the upper securing rod 265 extending through alignedopenings in each of the laminates 268 and 261 and in the end Walls 236and 237 while the lower securing rod 266 extends through alignedopenings provided in the laminates and the end walls. These securingrods serve to hold the laminates in place in the assembled relationshipas shown, the rods being slipped into position and being of such alength as to terminate short of the opposite end faces of the end wallsso as to permit suitable plugs of material to be inserted in the ends ofthe openings so as to retain the securing nuts in position.

Each of laminates 260 is provided with an upper and a lower bore 270 and271 as seen in FIG. 13 extending therethrough from the rear face thereofto the forward face thereof. Threaded openings 270 and 271' are disposedwithin each of these laminates and extend substantially normally to thebores 270 and 271 respectively. Threaded set screws 272 and 273 arethreadedly mounted within bores 270' and 271 respectively and areadapted to engage the outermost terminal ends 225 and 227" of the leads225 and 227 respectively. With this arrangement, it is apparent thateach of the leads 225 and each of the leads 227 is connected with one oflaminates 260 of the remotely controllable switch means. As pointed outpreviously, a single connection to each of laminates 260 would sufficein certain circumstances, the dual path arrangement being employedbecause of certain design considerations.

The remotely controllable switch means includes a movable contact meansindicated generally by reference numeral 276, this movable contact meansincluding a main housing member 277 having a cover plate 278 securedthereto by means of a pair of screws 280 extending through suitableopenings provided in member 278 and into tapped openings provided inmember 277. A central longitudinally extending tubular metallic member281 is permanently secured within the central portion of member 277 andextends through a central opening provided in member 278. Member 281 isprovided with screw threads on the inner surface thereof for a purposethat will appear more clearly hereinafter.

Members 277 and 278 are formed of a suitable insulating material such asBakelite or the like, member 277 being cut out in the interior thereofas seen most clearly in FIG. 13 to provide a first pair of recessedportions 283 and 284 in the face thereof, these recesses extendingthrough the side walls 285 and 286 of member 277. Communication isprovided between recesses 283 and 284 by a recess 288 formed in thisface of member 277. In a similar manner a pair of lower recesses 290 and291 are formed in the face of member 277 and open through the side edges285 and 286 of member 277.

Communication is provided between :reoesses 290 and 291 by means ofrecess 293 as seen in FIG. 12. Four identical contact members 295 aredisposed within recesses 283, 284, 290 and 291, the cover plate 278 whenin place relative to member 277 providing an arrangement which snuglyreceives contact members 295 yet ermits them to slide laterally of thesemembers. Compression springs 296 bear against the inner surfaces ofcontact members 295 and are seated within suitable recesses 297 providedin main body member 277. It is apparent that the springs 296 willnormally urge contact members 295 laterally outwardly into engagementwith the common contact means 258 at one side of the switch means andinto engagement with the laminates 260 at the other side of the switchmeans.

The upper contact members are connected with one another by a flexiblecopper strand wire 300 having the opposite ends thereof secured to thecontact members and the lower contact members 295 are connected in asimilar manner by a flexible wire 301, these wires being disposed withinrecesses 288 and 293 respectively whereby a good electrical connectionat all times is ensured between opposite sides of the switch means.

Referring particularly to FIG. 14, it will be noted that the upper andlower edges of member 277 are provided with chamfers 304 and 305, and ina similar manner the upper and lower edges of 'cover plate 278 areprovided with chamfers 307 and 308. These chamfers serve as cam surfacesfor engaging and operating limit stop switch means as will hereinafterbe explained. The chamfers are disposed at both the upper and loweredges as shown in the drawings, thereby making the movable contact meanssymmetrical so that it may be employed in either position thereof or inother words it may be employed in the position shown or a positionrotated from that shown.

Tubular member 281 of the movable contact means is threaded upon athreaded shaft 310 extending substantially throughout the length of theremotely controllable switch means, one end portion 311 of the threadedshaft being disposed within an opening 312 provided in end wall 237while the other end portion of the shaft extends through an opening 314provided in end wall 236 as seen in FIG. 8 and joins an enlarged portion315 which is inturn connected with a pinion 316 which meshes with thedrive gear output 318 of an electric motor indicated generally byreference numeral 320, the housing 321 of the electric motor supportinga bearing 322 which serves to journal the enlarged portion 315previously described.

Motor 320 is provided with a mounting bracket 325 which includes a largecentral threaded opening 326 adapted to receive a screw 328 extendingthrough a suitable opening in frame member 48 for securing the motorhousing to frame member 48. The mounting bracket also includes athreaded opening 330 which receives a screw 331 also extending through asuitable opening 335 provided in frame member 48 for securing the motorhousing in place relative to frame member 48.

As indicated in FIG. 4, the motor housing is provided with an openingthrough the under surface thereof through which suitable leads extendfor controlling the motor. Power is supplied to the motor through a lead336 which is connected through a fuse 337 to a lead 338 which in turn asseen at the righthand portion of FIG. 4 is connected at a point 340 tothe bus bar means 73 previously described. It is accordingly apparentthat power is transmitted directly from the input means of the apparatusto the motor 320. A pair of control leads 342 and 343 are provided forcontrolling operation of the motor in opposite directions, and theinterconnection of these leads with the components of the device will bemore fully hereinafter described.

A pair of limit stop switches are indicated generally by referencenumerals 345 and 346 as seen in FIG. 4, these limit stop switches beingmounted adjacent opposite ends of the remotely controllable contactmeans. Referring firstly to limit stop switch 345, a body means 350formed of suitable insulating material such as Bakelite or the like isconnected to the lower wall 235 of the remotely controllable switchmeans by a pair of screws 351 threaded into suitable tapped openingsprovided in wall 235.

As seen most clearly in FIG. 8 and FIG. 13, body means 350 is providedwith a first recessed portion 354 which is in communication with afurther central recessed portion 355. A pair of screws 357 and 358extend downwardly through suitable passages provided in body'means 350and are provided with enlarged heads which are disposed within recess354, contact washers 360 and 361 formed of copper or suitable goodelectrically conductive material being disposed beneath said heads. Nuts362 are threaded on the lower ends of screws 357 and 358 for receivingsuitable electrical contact members connected with leads hereinafterdescribed.

A plunger member indicated generally by reference numeral 365 includesan enlarged upper portion 366 and a smaller lower portion 367 whichextends slidably through a central opening provided in body means 350and in communication with the lower portion of recess 355. A contactwasher 370 engages the shoulder defined between portions 366 and 367,contact washer 370 being formed of a good electrically conductivematerial such as copper and being of such a dimension as to fit withinrecess 355 and providing a good electrical interconnection betweencontact washers 360 and 361. A compression spring 372 is disposed withinrecess 355 and engages against the under surface of contact surface 370to normally urge the contact washer and plunger member 365 upwardly intothe position shown in FIG. 13 so as to provide an electrical connectionbetween contact washers 360 and 361. Upward movement of plunger 365 islimited by a retaining spring 374 secured in a suitablecircumferentially extending groove provided in the lower portion 367 ofthe plunger member.

It will be noted that the upper end 375 of the enlarged portion 366 ofplunger member 365 is rounded so as to in effect define a cam surfacewhich will cooperate with the cam surface 308 defined at the bottom ofmember 278 of the movable contact means, the co-action between thesemembers being such that when the movable contact means reaches aposition adjacent the end of the remotely controllable switch means,plunger member 365 will be cammed downwardly due to contact between camsurface 308 and the upper cam surface 375 on the plunger member therebymoving contact washer 370 away from contact washers 360 and 361 therebybreaking the connection therebetween. The electrical circuit embodyingthis switch means will be hereinafter more fully de-' scribed.

Limit stop switch means 346 is of identical construction with limit stopswitch means 345, the body means 377 thereof being secured to the lowerwall portion 235 of the remotely controlled switch means by screws 378,and a pair of downwardly extending screws 380 and 381 identical withscrews 357 and 358 respectively being provided, a plunger member 383identical with plunger member 365 also being provided.

' It will be understood that the upper end portion of plunger member 383is provided with a rounded cam surface adapted to engage the cam surface305 provided on the lower portion of the movable contact means foropening the connection between contact screws 380 and 381 upon downwardmovement of plunger 383 as will be well curing a suitable lead to theinner portion thereof. A

wing nut 393 is mounted on the outer end of the stud for connecting theouter end thereof to a suitable ground lead.

A manually operable switch is indicated generally by reference numeral400 as seen in FIGS. 7, l0 and 16 and includes :an outwardly extendingmanually graspable operating member 401. This switch is of a three-waytype which is normally biased to a central position. Member 401 isconnected with a terminal 403 which is always connected to ground, andmay be moved in one direction to provide a circuit with terminal 404 ormay be moved in the opposite direction to provide a circuit withterminal 405 thereof, the connections of these terminals in theelect'rcal circuit being hereinafter described.

A receptacle indicated generally by reference numeral 410 is threaded onthe front plate 30 by means of nut and bolt assemblies 411 as seen inFIGS. 2 and 10 and is insulated from the front plate. This receptacle isprovided with four terminals numbered 413, 414, 415 and 416. Terminals413 and 414 are connected to ground as hereinafter more fully explained,while terminals 415 and 416 are connected with the remotely controllableswitch means as hereinafter described.

The forwardly extending portion of the receptacle is adapted to receivea mating plug means 420 which is in turn connected with a flexible cable421 which is connected with a foot operated control means 422. The footoperated control means includes a base member 425 upon which is rockablymounted an upper plate 426 which can be rocked to either side by anoperators foot to close the switches 427 or 428 depending on whether theoperator wishes to increase or decrease the amperage of the weldingcurrent.

Closing of one of these switches will cause the motor 320 to be drivenin one direction while closing of the other switch will cause the motorto be driven in the opposite direction thereby either increasing ordecreasing the output amperage as desired.

For example, switch 427 may be connected in circuit between contacts 413and 415 for closing the circuit to drive the motor in one directionwhile switch 428 may be connected in circuit between contacts 413 and416 for closing the circuit and driving the motor in the oppositedirection as will be well understood.

Referring now to FIG. 16, the circuit for driving the motor in oppositedirections may be more fully understood. As seen in this figure, poweris provided to the motor through leads 336 and 338 as previouslydescribed. The leads 342 and 343 for driving the motor in oppositedirections extend respectively to the contacts 381 and 358 of the limitstop switch means 346 and 345 respectively. It is apparent that as longas these limit stop switch means are closed as is the normal condition,the circuit will then be completed from limit stop switch means 346through lead 430 to terminal 416 of the receptacle 410 while the circuitwill also be closed through limit stop switch means 345 and lead 431 toterminal 415 of the receptacle 410. Terminal 413 of the receptacle isconnected to the ground means 385 by lead 435 while terminal 414 may beconnected by means of lead 436 to the metallic framework of theapparatus to provide an equipment safety ground. It will also be notedthat the central terminal 403 of manual switch 400 is connected toground means 385 by means of a lead 437.

Terminal 404 of the manual switch means is connected with contact 380 ofthe limit stop switch means 346 by means of a lead 440 and terminal 405.of the manual switch means 400 is connected with contact 357 of limitstop switch means 345 by means of lead 441.

In operation, the input means 65 is connected with a suitable source ofcurrent such as a constant 80 volt potential DC. power source. Theswitch means 166, 170, 171 and 172 are then closed to provide theminimum required welding current. As pointed out previously, theseswitch means may be operated'to vary the output amperage in incrementsfrom 40 amperes in a range from 40 amperes to 280 amperes. Once thisminimum required welding current is obtained, the remotelycontrolledswitch means may be utilized for attaining the .desiredwelding current over 'a continuous working range from the minimumsetting to the minimum setting plus 50 amperes. When the welder desiresto vary the current in increments of approximately two amperes the footoperated controlmeans 422 is actuated while the welder is actuallywelding, and the welder can readily obtain either increases or decreasesin the welding current by closing either the switch 427 or 428 of theremote control means by means of rocking his foot in differentdirections thereby causing the motor to be actuated in either onedirection or the other for moving the movable contact means 276 of theremotely controlled switch back and forth within this remotelycontrollable switch means.

It is apparent that power is supplied to one side of the motor and thatthe circuit is completed through the limit stop switches and the remotecontrol unit to ground.

The remote control unit 422 is normally biased to a neutral positionsuch that when not actuated by the welder both of switches 427 and 428will be open so that the circuit through the motor is not closed and themotor will be de-energized.

It will be noted that manual switch means 400 is connected in parallelwith the remote control means so that the output current can also bereadily controlled at the unit by actuating the manual switch means ifdesired.

When the movable contact means 276 approaches one end of the remotelycontrollable switch means, one or the other of the limit stop switchmeans 345 or 346 may be opened thereby opening the circuit from themotor through one of the remote switches 427 or 428. It is thenimpossible to drive the movable contact means any further in thisdirection, and accordingly, the other remote switch must then beactuated to move the movable contact means in the opposite directionuntil the opposite limit stop means may again open the circuit and limitthe movement of the movable contact means in such opposite direction.

It is apparent from the foregoing that there is provided a new and novelremotely controllable current regulator which is especially adapted foruse with welding equipment and which includes a first set of manuallyoperable switches for providing adjustment of the output current inrelatively large increments and over a wide range, and which furtherincludes a remotely controllable switch means for providing from aremote position adjustment of the welding current in relatively smallincrements so as to continuously provide optimum welding conditionsthroughout a welding operation.

Limit stop switch means is provided for limiting movement of theremotely controlled switch means in opposite to thereby preventexcessive movement and damage to this switch means. The over-allconstruction of the apparatus is such as to provide a compact and veryrigid and well protected unit while at the same time providing aconstruction which affords a maximum degree of accessibility of thecomponents and which permits ready circulation of air thereabout toensure adequate cooling.

As this invention may be embodied in several forms without departingfrom the spirit or essential characteristics thereof, the presentembodiment is therefore illustrative and not restrictive, and since thescope of the invention is defined by the appended claims, all changesthat fall within the metes and bounds of the claims or that form theirfunctional as well as coniointly cooperative equivalents are there-foreintended to be embraced by those claims.

I claim:

1. A remotely controllable current regulator for supplying current towelding equipment comprising input means adapted to be connected to asource of constant electrical potential, output means adapted to beconnected to welding equipment, first resistance means comprising aplurality of resistances each connected in parallel with one another andin series between said input means and said output means, separateindividually, manually controllable switch means operatively associatedwith each of said resistances for selectively connecting each of saidresistances with said output, said resistances providing rather largestepsin the amount of amperage provided therethrough, second resistancemeansconnected with said input means, remotely operable switch meansincluding a common contact means at one side thereof connected with saidoutput means and a plurality of separate contacts insulated from oneanother and connected with different portions of said second resistancemeans to provide different amounts of electrical current in relativelysmall increments to said separate contacts, movable contact means forselectively connecting different ones of said separate contacts withsaid common contact means and said output means so that said separatecontacts are in series between said input and said output means and inparallel With said first resistance means, and means for remotelycontrolling the movement of said movable contact means for selectivelyengaging different ones of said separate contacts and remaining inengagement with a desired separate contact as long as desired to providefine adjustments of amperage and to enable a desired adjusted amperageto be maintained at said output means as long as desired and furtherwherein said amperage may be readily increased or decreased as desired.

2. Apparatus as defined in claim 1 wherein said means for remotelycontrolling the movement of said movable contact means comprises a footswitch spaced a substantial distance from said movable contact means.

3. Apparatus as defined in claim 1 including drive means drivinglyconnected with said movable contact means for moving said movablecontact means, said drive means being connected in an electrical circuitwith said input means, and limit stop switch means connected in thecircuit with said drive means and engageable with said movable contactmeans at opposite limits of movement of said movable contact means so asto limit movement of the movable contact means in either direction, saidlimit stop switch means including a switch member which is normallyresiliently urged in one direction to close a circuit through said drivemeans, said last-mentioned switch member having a cam surface at one endportion thereof and being reciprocably mounted, said movable contactmeans having a cam surface at one end portion thereof and beingreciprocably mounted, said movable contact means having cam surfacemeans thereon for engaging the cam surface on said switch member of thelimit stop switch means to reciprocate said switch member so as to opena circuit through said drive means to thereby de-energize the drivemeans.

4. Apparatus as defined in claim 1 wherein said movable contact meanscomprises a supporting means operatively driven by drive means, and apair of contact members supported by said support means, meansresiliently urging said contact members in opposite directions so as torespectively engage said common contact means and individual ones ofsaid separate contact means, and means operatively electricallyconnecting said contact members so as to provide an electricalconnection between said common contact means and said separate contacts.

5. Apparatus as defined in claim 1 wherein said movable contact meansincludes a housing means, said housing means defining recessed portionstherewithin, four contact members separate and insulated from oneanother, each of said contact members being slidably positioned withinone of said recessed portions, said contact members defining an upperpair of contact members and a lower pair of contact members, the contactmembers of each pair being normally resiliently urged in oppositedirections, and means providing an electrical connection between thecontact members of each pair of contact members to define a pair ofparallel resistance paths each adapted to carry half of the currentwhereby the over-all dimension of the apparatus may be reduced to make amore compact and cheaper arrangement.

6. A current regulator for supplying current to welding equipmentcomprising input means for connection to a source of constant electricalpotential, output means for connection to welding equipment, firstresistance means comprising a plurality of resistances each connected inparallel with one another and in series between said input means andsaid output means, means for selectively connecting and disconnectingcertain ones of said first resistance means between said input and saidoutput means,

each of said resistance means providing rather large steps in the amountof amperage provided therethrough, sec- 'ond resistance means connectedin parallel with said first resistance means and in series between saidinput means and said output means, said second resistance means ineluding selectively operable means for providing electrical current inrelatively small increments in the amount of I amperage providedtherethrough;

References Cited by the Examiner Stevens 32394 JOHN F. COUCH,PrimaryExaminer. v I

A. D. PELLINEN, Assistant Examiner.

1. A REMOTELY CONTROLLABLE CURRENT REGULATOR FOR SUPPLYING CURRENT TOWELDING EQUIPMENT COMPRISING INPUT MEANS ADAPTED TO BE CONNECTED TO ASOURCE OF CONSTANT ELECTRICAL POTENTIAL, OUTPUT MEANS ADAPTED TO BECONNECTED TO WELDING EQUIPMENT, FIRST RESISTANCE MEANS COMPRISING APLURALITY OF RESISTANCES EACH CONNECTED IN PARALLEL WITH ONE ANOTHER ANDIN SERIES BETWEEN SAID INPUT MEANS AND SAID OUTPUT MEANS, SEPARATEINDIVIDUALLY, MANUALLY CONTROLLABLE SWITCH MEANS OPERATIVELY ASSOCIATEDWITH EACH OF SAID RESITANCES FOR SELECTIVELY CONNECTING EACH OF SAIDRESISTANCES WITH SAID OUTPUT, SAID RESISTANCES PROVIDING RATHER LARGESTEPS IN THE AMOUNT OF AMPERAGE PROVIDED THRERETHROUGH, SECONDRESISTANCE MEANS CONNECTED WITH SAID INPUT MEANS, REMOTELY OPERABLESWITCH MEANS INCLUDING A COMMON CONTACT MEANS AT ONE SIDE THEREOFCONNECTED WITH SAID OUTPUT MEANS AND A PLURALITY OF SEPARATE CONTACTSINSULATED FROM ONE ANOTHER AND CONNECTED WITH DIFFERENT PORTIONS OF SAIDSECOND RESISTANCE MEANS TO PROVIDE DIFFERENT AMOUNTS OF ELECTRICALCURRENT IN RELATIVELY SMALL INCREMENTS TO SAID SEPARATE CONTACTS,MOVABLE CONTACT MEANS FOR SELECTIVELY CONNECTING DIFFERENT ONES OF SAIDSEPARATE CONTACTS WITH SAID COMMON CONTACT MEANS AND SAID OUTPUT MEANSSO THAT SAID SEPARATE CONTACTS ARE IN SERIES BETWEEN SAID INPUT AND SAIDOUTPUT MEANS AND IN PARALLEL WITH SAID FIRST RESISTANCE MEANS, AND MEANSFOR REMOTELY CONTROLING THE MOVEMENT OF SAID MOVABLE CONTACT MEANS FORSELECTIVELY ENGAGING DIFFERENT ONES OF SAID SEPARATE CONTACTS ANDREMAINING IN ENGAGEMENT WITH A DESIRED SEPARATE CONTACT AS LONG ASDESIRED TO PROVIDE FINE ADJUSTMENTS OF AMPERAGE AND TO ENABLE A DESIREDADJUSTED AMPERAGE TO BE MAINTAINED AT SAID OUTPUT MEANS AS LONG ASDESIRED AND FURTHER WHEREIN SAID AMPERAGE MAY BE READILY INCREASED ORDECREASED AS DESIRED.